Alayer of material that block the transfer of heat between the air inside and outside a building is called
a. an active solar system.
b. a solar cell.
c. a heat exchanger.
d. insulation.

If you touch a hot light bulb and get burned, that is an example of a. radiation b. convection c. conduction

Aparticle travels in a circular orbit of radius 21 m. its speed is changing at a rate of 23.1 m/s2 at an instant when its speed is 37.2 m/s. what is the magnitude of the acceleration (in m/s? ) of the particle?

Oxygen undergoes an isentropic expansion from 120 degree c and 280 kpa absolute to 140 kpa absolute. determine the final temperature of the oxygen and the amount of work per kg of o_2 produced in the process if it is adiabatic.